Small diameter tube inflation protection welding device

Abstract

The utility model relates to welding tool technical field, especially a small diameter pipe inflation protection welding device. Be applicable to small diameter pipe head welding operation of chemical industry or pressure vessel. Including inflation pad, quick male and female joint and breather pipe, inflation pad sets up inflation cavity, and the one side end surface of inflation pad is equipped with quick male and female joint, and inflation cavity is linked with quick male and female joint, and quick male and female joint is connected with breather pipe, and the other side end surface of inflation pad is equipped with a plurality of gas outlet holes, and gas outlet hole is communicated with breather pipe through inflation cavity, and the pipe cover of welding pipe is waited for on inflation pad, and breather pipe is passed into welding protection gas, and welding protection gas is passed into the pipe cavity of welding pipe through gas outlet hole, and the head of welding pipe is waited for. By filling in the protection gas in the inside and forming local air chamber at the back of weld, can effectively isolate air, ensure that the back of weld is not oxidized, obtain dense, beautiful weld back forming.

Description

Technical Field

[0001] This utility model relates to the field of welding tooling technology, and in particular to a gas-protected welding device for small-diameter pipes. It is suitable for welding small-diameter pipe heads in chemical plants or pressure vessels. Background Technology

[0002] In the manufacturing process of pressure vessels and piping systems, circumferential welding of small-diameter end caps to pipe bodies is frequently involved. This includes pipes with diameters DN ≤ 25 mm and lengths L ≥ 150 mm, or pipes with diameters DN ≤ 45 mm and lengths L ≥ 200 mm. Currently, segmented welding is generally used to ensure weld quality for such small-diameter pipes. This welding method has significant drawbacks: First, segmented welds leave at least 3 to 6 weld joints, making the process cumbersome; second, segmented welding leads to uneven heat input, making it difficult to control weld deformation, resulting in poor back-side protection and defects such as oxidation and lack of fusion; third, this method has low welding efficiency, severely restricting production pace and failing to meet the needs of mass production. Therefore, there is an urgent need for a gas-protected welding device that can achieve high quality and high efficiency. Utility Model Content

[0003] The purpose of this utility model is to overcome the shortcomings of the existing technology and provide a small-diameter pipe inflation tool with reasonable structure and simple operation, which can effectively reduce the number of welding joints, improve welding efficiency and back protection effect of weld, and ensure that the weld is formed beautifully.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A gas-shielded welding device for small-diameter pipes includes a gas-shielded welding pad, a quick-connect male and female connector, and a vent pipe. The gas-shielded welding pad has a gas-shielded cavity. A quick-connect male and female connector is provided on one end face of the gas-shielded welding pad, and the gas-shielded cavity is connected to the quick-connect male and female connector. The quick-connect male and female connector is connected to the vent pipe. Multiple vent holes are provided on the other end face of the gas-shielded welding pad, and the vent holes are connected to the vent pipe through the gas-shielded cavity. The pipe to be welded is covered on the gas-shielded welding pad. Welding shielding gas is introduced into the vent pipe and introduced into the cavity of the pipe to be welded through the vent holes. A welding end cap is then welded onto the pipe.

[0005] Multiple vent holes on the other end face of the gas-filled welding pad are distributed in a matrix along the center of the end face. The vent holes are located inside the cavity of the pipe to be welded, and are close to but not in contact with the inner wall of the pipe to be welded.

[0006] The gas-filled welding pad has a locking sealing groove, which is annular. The distance between the locking sealing groove and the center of the gas-filled welding pad is greater than the distance between the vent hole and the center of the gas-filled welding pad.

[0007] A sealing gasket is provided inside the locking sealing groove. The sealing gasket is made of silicone or fluororubber and has a quarter-circular arc surface in cross section. The height of the sealing gasket near the center of the gas-filled pad is lower than the height of the sealing gasket away from the center of the gas-filled pad.

[0008] It also includes a split-type variable diameter plate, which has a snap-fit ​​cavity and a vent. An inflatable welding pad is placed in the snap-fit ​​cavity. The inflatable welding pad is equipped with connecting bolts. The inflatable welding pad is connected to the split-type variable diameter plate as a whole by connecting bolts and connecting nuts. The number and position of the vent on the split-type variable diameter plate correspond to the number and position of the air outlet on the inflatable welding pad. The vent is inserted into the air outlet.

[0009] The split-diameter reducing plate is provided with a locking sealing groove, and a sealing gasket is provided in the locking sealing groove. The sealing gasket is provided with multiple layered linings, which are arranged at intervals.

[0010] The height of the multiple layered lining sheets decreases sequentially toward the center of the gas-filled welding pad. The multiple layered lining sheets and the sealing gasket form a multi-ring lining, and the pipe to be welded is in close contact with the multi-ring lining.

[0011] Compared with the prior art, the present invention has the following significant advantages: Improved efficiency and quality: The gas-filled welding pad can be engaged with the grippers of the welding positioner, enabling continuous welding and reducing the number of existing weld joints. Simultaneous gas filling and welding reduce gas filling preparation time by more than 30%, significantly increasing production efficiency. The continuous welding process ensures uniform heat input, greatly improving weld quality.

[0012] Excellent back protection: By filling the back with protective gas and forming a local gas chamber on the back of the weld, air can be effectively isolated to ensure that the back of the weld is not oxidized, resulting in a dense and beautiful weld back formation, achieving the ideal welding effect of single-sided welding with double-sided forming.

[0013] Highly adaptable and easy to operate: The tooling structure is simple, the manufacturing cost is low, and it is easy to install and disassemble. It can be widely used in welding scenarios for small-diameter pipe heads of different specifications. When used with a welding positioner, it is easy to achieve automated production. Attached Figure Description

[0014] Figure 1 A schematic diagram of a gas-protected welding device for small-diameter pipes; Figure 2 for Figure 1 Side view; Figure 3 Schematic diagram of the gas-protected welding device for small-diameter pipes combined with the pipe to be welded; Figure 4 Schematic diagram of the gas protection status of the gas-filled protective welding device for small-diameter pipes; Figure 5This is a schematic diagram of a split-type variable diameter disc assembly; Figure 6 for Figure 5 Schematic diagram of the exploded structure; The markings in the diagram are as follows: 1. Gas-filled welding pad; 2. Gas-filled cavity; 3. Vent hole; 4. Quick male and female connector; 5. Vent pipe; 6. Locking sealing groove; 7. Sealing gasket; 8. Split reducing plate; 9. Vent nozzle; 10. Connecting bolt; 11. Connecting nut; 12. Layered lining; 13. Pipe to be welded; 14. End cap. Detailed Implementation

[0015] A gas-shielded welding device for small-diameter pipes includes a gas-shielded welding pad 1, a quick-connect male and female connector 4, and a vent pipe 5. The gas-shielded welding pad 1 has a gas-shielded cavity 2. A quick-connect male and female connector 4 is located on one end face of the gas-shielded welding pad 1, connecting the gas-shielded cavity 2 to the quick-connect male and female connector 4, which in turn connects to the vent pipe 5. Multiple vent holes 3 are located on the other end face of the gas-shielded welding pad 1, connecting to the vent pipe 5 through the gas-shielded cavity 2. The pipe to be welded 13 is fitted onto the gas-shielded welding pad 1. Welding shielding gas is introduced through the vent pipe 5 and enters the cavity of the pipe to be welded 13 through the vent holes 3. A welding end cap 14 is then welded onto the pipe to be welded 13. Installation is convenient and quick by fitting the pipe to be welded 13 onto the gas-shielded welding pad 1, and the device can be reused. Welding is performed on pipes of different diameters. The external air supply is connected to the vent pipe 5 via the quick male and female connector 4. When the gas-filled welding pad 1 is used in conjunction with the welding positioner, the rotation of the gas-filled welding pad 1 does not affect the air supply of the external air supply.

[0016] Multiple vent holes 3 on the other end face of the gas-filled welding pad 1 are distributed in a matrix along the center of the end face. The vent holes 3 are located inside the cavity of the tube 13 to be welded, and are close to but not in contact with the inner wall of the tube 13 to be welded. Welding shielding gas is uniformly introduced through the multiple vent holes 3. The welding shielding gas spreads along the tube wall and exits through the gap between the tube 13 to be welded and the end cap 14 until the weld is completely formed. During this process, the welding shielding gas is always conducted through the gap between the tube 13 to be welded and the end cap 14, effectively isolating air.

[0017] A locking and sealing groove 6 is formed on the gas-filled welding pad 1. The locking and sealing groove 6 is annular, and the center distance between the locking and sealing groove 6 and the center of the gas-filled welding pad 1 is greater than the center distance between the vent hole 3 and the center of the gas-filled welding pad 1. The tube 13 to be welded is fastened into the annular locking and sealing groove 6 to prevent the welding shielding gas from leaking out along the lower part of the tube 13 to be welded.

[0018] A sealing gasket 7 is provided within the locking sealing groove 6. The sealing gasket 7 is made of silicone or fluororubber, and its cross-section is a quarter-circular arc surface. The height of the sealing gasket 7 near the center of the gas-filled welding pad 1 is lower than the height of the sealing gasket 7 away from the center of the gas-filled welding pad 1. This structure helps the sealing gasket 7 to fit snugly against the outer edge of the tube 13 to be welded. At the same time, the tube 13 to be welded presses against the soft material sealing gasket 7 by its own weight, further improving the sealing effect. Furthermore, no separate locking clip is required for fixation; the seal is achieved through weight and the adhesion between the materials. It should be noted that in this case, a complete seal is not required; it is sufficient to ensure that the welding shielding gas always flows along the gap to protect the weld.

[0019] It also includes a split-type reducing plate 8, which has a locking cavity and a vent 9. An inflatable welding pad 1 is placed inside the locking cavity, and the inflatable welding pad 1 is equipped with connecting bolts 10. The inflatable welding pad 1 is connected to the split-type reducing plate 8 as a whole through the connecting bolts 10 and connecting nuts 11. The number and position of the vents 9 on the split-type reducing plate 8 correspond to the number and position of the vent holes 3 on the inflatable welding pad 1, and the vents 9 are inserted into the vent holes 3. When welding pipes of different diameters, size adaptation and replacement can be achieved by replacing the split-type reducing plate 8 with one of the corresponding size.

[0020] The split-diameter reducing plate 8 is provided with a locking sealing groove 6, and a sealing gasket 7 is provided inside the locking sealing groove 6. Multiple layered lining sheets 12 are provided on the sealing gasket 7, and the multiple layered lining sheets 12 are arranged at intervals. The height of the multiple layered lining sheets 12 decreases sequentially towards the center of the gas-filled welding pad 1. The multiple layered lining sheets 12 and the sealing gasket 7 form a multi-ring liner, and the pipe to be welded 13 is in close contact with the multi-ring liner. The pipe to be welded 13 is pressed onto the multi-ring liner. When the end of the pipe to be welded 13 is uneven, the sealing effect can be improved by individually attaching the multiple layered lining sheets 12. When the pipe to be welded 13 is directly inserted into the gaps between the multiple layered lining sheets 12, the adjacent layered lining sheets 12 are in contact with the inner and outer walls of the pipe to be welded, which can also improve the sealing effect.

[0021] Before welding, the device is fastened to the pipe 13 to be welded. Welding shielding gas is introduced into the back area of ​​the circumferential weld. Inert shielding gas (such as argon) is introduced into the outlet port 3 through the quick-connect male and female connector 4 and the gas vent 5. The gas overflows from the outlet port 3, effectively isolating the back of the high-temperature weld from air and preventing oxidation. When used with a welding positioner, the workpiece can be rotated at a uniform speed while the welding torch is fixed for welding, thereby achieving continuous and uniform automated or semi-automated welding, replacing traditional segmented welding.

Claims

1. A gas-insulated protective welding device for small-diameter pipes, characterized in that... The assembly includes an inflatable welding pad (1), a quick-connect male and female connector (4), and a vent pipe (5). The inflatable welding pad (1) has an inflatable cavity (2). A quick-connect male and female connector (4) is provided on one side of the inflatable welding pad (1). The inflatable cavity (2) is connected to the quick-connect male and female connector (4). The quick-connect male and female connector (4) is connected to the vent pipe (5). Multiple vent holes (3) are provided on the other side of the inflatable welding pad (1). The vent holes (3) are connected to the vent pipe (5) through the inflatable cavity (2). The tube to be welded (13) is covered on the inflatable welding pad (1). Welding shielding gas is introduced into the vent pipe (5). Welding shielding gas is introduced into the tube cavity of the tube to be welded (13) through the vent holes (3). A welding end cap (14) is welded onto the tube to be welded (13).

2. The gas-filled protective welding device for small-diameter pipes according to claim 1, characterized in that... Multiple air vents (3) on the other end face of the gas-filled welding pad (1) are distributed along the center matrix of the end face. The air vents (3) are located inside the cavity of the tube (13) to be welded. The air vents (3) are close to but do not contact the inner wall of the tube (13) to be welded.

3. The gas-filled protective welding device for small-diameter pipes according to claim 1, characterized in that... The gas-filled welding pad (1) has a locking sealing groove (6) which is annular. The center distance between the locking sealing groove (6) and the gas-filled welding pad (1) is greater than the center distance between the air outlet (3) and the gas-filled welding pad (1).

4. The gas-insulated protective welding device for small-diameter pipes according to claim 3, characterized in that... A sealing gasket (7) is provided inside the locking sealing groove (6). The sealing gasket (7) is made of silicone or fluororubber. The cross-section of the sealing gasket (7) is a quarter-circular arc surface. The height of the sealing gasket (7) near the center end of the gas-filled solder pad (1) is lower than the height of the sealing gasket (7) away from the center end of the gas-filled solder pad (1).

5. The gas-insulated protective welding device for small-diameter pipes according to claim 2, characterized in that... It also includes a split-diameter plate (8), which is provided with a snap-fit ​​cavity and a vent (9). An inflatable welding plate (1) is placed in the snap-fit ​​cavity. A connecting bolt (10) is provided on the inflatable welding plate (1). The inflatable welding plate (1) is connected to the split-diameter plate (8) as a whole by the connecting bolt (10) and the connecting nut (11). The number and position of the vent (9) on the split-diameter plate (8) correspond to the number and position of the air outlet (3) on the inflatable welding plate (1). The vent (9) is inserted into the air outlet (3).

6. The gas-filled protective welding device for small-diameter pipes according to claim 5, characterized in that... The split-diameter plate (8) is provided with a locking sealing groove (6), and a sealing gasket (7) is provided in the locking sealing groove (6). The sealing gasket (7) is provided with multiple layered linings (12), and the multiple layered linings (12) are arranged at intervals.

7. The gas-insulated protective welding device for small-diameter pipes according to claim 6, characterized in that... The height of the multiple layered linings (12) decreases sequentially toward the center of the gas-filled welding pad (1). The multiple layered linings (12) and the sealing gasket (7) form a multi-ring lining, and the tube to be welded (13) is in close contact with the multi-ring lining.

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